<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .header{
            width: 960px;
            height: 40px;
            background: #55a8ea;
            margin: 0 auto;
        }
        ul li {
            width: 100px;
            height: 40px;
            text-align: center;
            cursor: pointer;
            line-height: 40px;
            float:left;
            margin-left: 20px;
            list-style-type: none;
        }
        ul li a{
            text-decoration: none;
        }
        .header ul li.active{
            background: #00619f;
        }
         ul li:hover{
            background: #00619f;
       }
    </style>
</head>
<body>
<div class="header">
        <ul>
            <li class="active"><a href="#">首页</a></li>
            <li><a href="#">网站建设</a></li>
            <li><a href="#">程序开发</a></li>
            <li><a href="#">网络营销</a></li>
            <li><a href="#">企业UI</a></li>
            <li><a href="#">案例展示</a></li>
            <li><a href="#">联系我们</a></li>
        </ul>

</div>

</body>
</html>